222 
NATURAL HISTORY. 
from the month of July to October; and they are sold at 
a very moderate price. 
From this animal the Oyster differs very little, except 
in the thickness of its shell, and its greater imbecility. The 
oyster, like the muscle, is formed with organs of life and 
respiration, with intestines which are very voluminous a 
liver, lungs, and heart. Like the muscle, it is self-impreg- 
nated ; and the shell, which the animal soon acquires, serves 
it for its future habitation. Like the muscle, it opens its 
shell to receive the influx of water, and like that animal is 
strongly attached to its shells both above and below. ’ 
The oyster differs from the muscle in being utterly unable 
to change its situation. It is entirelv without that ton»ue 
which we saw answering the purposes of an arm in the 
other animal ; but nevertheless is often attached very firmly 
to any object it happens to approach. Nothing is so common 
in the rivers of the tropical climates as to see oysters "row- 
ing even amidst the branches of the forest. Many°trees 
which grow along the banks of the stream, often bend their 
branches into the water, and particularly the mangrove 
which chiefly delights in a moist situation. To these the 
oysters hang in clusters, like apples upon the most fertile 
tree; and in proportion as the weight of the fish sinks the 
plant into the water, where it still continues growing, the 
number of oysters increase, and hang upon tile branches. 
This is effected by means of a glue proper to themselves, 
which, when it cements, the joining is as hard as the shell, 
and is broken with equal difficultly. 
Oysters usually cast their spawn in May, which at first ap- 
pears like drops of candle-grease, and sticks to any hard sub- 
stance it falls upon. These are covered with a shell in two or 
three days ; and in three years the animal is large enough to 
be brought to market. As they invariably remain in the 
places where they are laid, and as they grow without any other 
seeming food than the influx of sea-water, it is the custom at 
Colchester, and other parts of England, where the tide settles 
in marshes on land, to pick up great quantities ofsmall ovs- 
ters along the shore, which when first gathered, seldom exceed 
the size of a sixpence. These are deposited in beds where the 
tide comes in, and in two or three years grow to a tolerable 
size. They are said to be better tasted for being thus shel- 
tered from the agitation of the deep ; and a mixture of fresh 
water entering into these repositories, is said to improve their 
flavour, and to increase their growth and fatness. 
I he oysteis, however, which are prepared in this manner, 
are by no means so large as those found sticking to rocks at 
